Optical coherence tomography (OCT) has become the standard of care for diagnosis and following treatment of many pathological ophthalmic conditions in the posterior and anterior human eye. However, conventional OCT systems do not capture volumes instantaneously and are therefore subject to artifacts due to patient motion. While a subject's voluntary motion may be mitigated with a fixation target, involuntary motion such as micro-saccades, drifts, or tremors may still corrupt OCT volumetric data and associated en face summed volume projections (SVPs). In previous work, real-time tracking for motion compensated OCT has focused on retinal imaging. However, as the clinical prominence of volumetric anterior segment OCT increases, the need for real-time motion-correction solutions designed for anterior segment imaging has become apparent.
Conventional OCT retinal imaging systems employ a telescope to image the beam scanning pivot onto the pupil plane of the patient. To maximize collection efficiency of back-scattered light and to minimize aberrations and vignetting, the scanning beam should optimally rotate through the central cornea, and the scan pivot should be imaged at the center of the ocular pupil. Moreover, specific retinal features, such as the cone photoreceptors and Henle's Fiber Layer (HFL), exhibit back-reflected intensity dependence on pupil entry position. Commercial OCT systems employ an infrared (IR) pupil camera to allow alignment of the OCT beam onto the patient's eye and to vary pupil entry position. However, such systems are still vulnerable to lateral patient motion and depend upon active involvement of the photographer to obtain and maintain alignment.
In view of the foregoing, there is a desire to provide improved OCT systems and methods for retinal imaging.